A novel E box/AT-rich element is required for muscle-specific expression of the sarcoplasmic reticulum Ca2+-ATPase (SERCA2) gene.
The cardiac/slow twitch sarcoplasmic reticulum (SR) Ca2+-ATPase gene (SERCA2 ) encodes a calcium transport pump whose expression is regulated in a tissue- and development-specific manner. Previously we have identified two distinct positive regulatory regions (bp -284 to -72 and -1815 to -1105) as important for SERCA2 promoter activity. Here we demonstrate that the SERCA2 distal promoter region functions like an enhancer by activating a heterologous promoter (TK) in a muscle cell-specific manner. Through deletion analysis a core enhancer region was delimited to the -1467 to -1105 bp fragment. We identified the E box/AT-rich element located at -1115 bp as critical for maximal enhancer activity. Gel mobility shift studies revealed that this E box/AT-rich element specifically binds a protein which is induced during Sol8 myogenesis. This region includes two other cis -acting elements, CArG and MCAT, which also bind specific nuclear protein complexes from Sol8 myotubes. Mutagenesis of each of these sites resulted in decreased SERCA/TK-CAT promoter activity. Based on these data, we propose that the E box/AT-rich element may contribute along with CArG and MCAT elements to the overall activation and regulation of the SERCA2 gene promoter.
Baker
D L
DL
Division of Cardiology, University of Cincinnati College of Medicine, ML542, 231 Bethesda Avenue, Cincinnati, OH 45267, USA.
Dave
V
V
Reed
T
T
Misra
S
S
Periasamy
M
M
D016475:3T3 Cells; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D000252:Calcium-Transporting ATPases / Q000235:genetics*; D002460:Cell Line; D002874:Chromosome Mapping; D004247:DNA / Q000235:genetics* / Q000378:metabolism; D016172:DNA Fingerprinting; D004742:Enhancer Elements, Genetic; D005786:Gene Expression Regulation; D051379:Mice; D008969:Molecular Sequence Data; D018482:Muscle, Skeletal / Q000201:enzymology*; D016297:Mutagenesis, Site-Directed; D009206:Myocardium / Q000201:enzymology; D009687:Nuclear Proteins / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012519:Sarcoplasmic Reticulum / Q000201:enzymology*
D009687:Nuclear Proteins; D004247:DNA; D000252:Calcium-Transporting ATPases